Gallup, one of the biggest polling organizations, has decided to take a step back from the frenzied who’s-in-first coverage and focus solely — for now, at least — on what the American public thinks about issues.

The Gallup Organization has identified a series of factors that contributed its overestimation of support for Mitt Romney in the 2012 presidential election, including problems with its survey sample and methodology, according to an in-depth analysis...